A sleeve creates an opening known as a penetration or hole between floors of buildings or other structures essential for various trades (i.e. electrical, plumbing, sprinkler fitting). Plumbing processes and mechanical needs are routed using penetrations to maximize efficiency and minimize materials used. Large penetrations called shafts are utilized to connect each floor for large duct work and system pipes, however congestion in those shafts is avoided by having drain and vent pipes plumbed through penetrations. Electrical and data needs can be brought up through the floor as well.
In buildings with floors made of metal decking and concrete, or just concrete, passages are created utilizing, for example, a core drilling method or a boxing out method. The core drilling method generally includes a core drill rig, specialized wet core bits and water. The concrete is poured, creating the floor without any penetration. Once the concrete cures, holes of various sizes are drilled using a core drill rig with a wet core bit. This method requires a water source to keep the bit cool, two people (one to keep watch below while the other cuts), clean up and a lot of time.
The boxing out method includes structures and material such as wood frames or forms and Styrofoam or dense insulation foam board. The boxing out method allows for the deck to retain structural integrity during a concrete pour. This method is discouraged due to the resulting seams created from multiple concrete pours called cold joints. Cold joints are of inferior quality when a water tight finished floor is necessary. The boxing out method is also time-consuming.
The Sleeve method avoids potentials for cold joints however there are several disadvantages. If a sleeve is wrongly placed (knocked over) and concrete is poured you must resort to core drilling to make the correction. This often requires cutting into the existing sleeve. Since most sleeves are made with ferrous materials, cutting time is increased. The anchors do not allow for easy physical manipulation. Cutting the anchors along with the decking material after the pour of concrete is also difficult since the anchors consist of high strength steel. The PVC used in this method easily catches on fire when the decking is finally cut through with a torch. Tin sleeves are easy to cut to meet the profile of the deck, but the material is thin and can easily be dented or torn off due to its lack of structural strength. Duct tape, styrofoam, and insulation boards are used to fill in the odd shaped voids, however some problems arise with the use of these materials. Keeping the foam in place is difficult, the duct tape used to seal around the base and seams does not adhere well when the weather is cold, and the insulation boards along with the other materials burns and melts easily. Other weather factors prevent the surfaces from being dry.